This program project application is designed to explore mechanisms of genetic diseases that affect striated muscle, how these diseases are affected by the normal aging process, and it also seeks to develop gene therapy approaches for treating these diseases. The applicants are a diverse and broad based group of researchers with interests in ageing, muscle structure-function relationships, genetic muscle diseases, and gene therapy. The affiliated projects focus on cardiac and skeletal muscle disease and bring together the fields of gerontology, physiology, molecular biology, and genetics. Project 1 seeks to develop a new class of adenoviral vectors that lacks all viral genes and that can transfer large genes into striated muscle of young and old animals. Project 2 aims to develop a better understanding of the role of the dystrophin associated protein complex in striated muscle, how mutations in genes that encode the proteins of this complex lead to muscular dystrophies (CDs), and how normal ageing contributes to the pathology of the MDs. Project 3 explores hypertrophic cardiomyopathies, and aims to develop adenoviral vector mediated gene transfer to the heart as a mechanism to correct inherited cardiac diseases at different stages of disease progression. These projects will be supported by four Core Laboratories. Core 1 is an administrative core to coordinate the separate projects. Core 2 is a Viral Vector Core to provide large scale growth of adenoviral vectors and assistance with their use. Core 3 is an Animal Models/Immunology Core that will house the animals for these studies, provide veterinary care and assistance with protocols, and which will also provide detailed immunological assays to study immune responses to adenoviral vector transfer. Core 45 us a Contractility Core that will measure changes in muscle contractile properties during ageing of normal and diseased muscle and following adenoviral based gene transfer to striated muscles. These projects will lead to a greater understanding of muscle diseases and ageing, and will contribute to the development of therapies for inherited diseases of skeletal and cardiac muscle.